SWITCH AS-RKR 5247923 - Caterpillar

Personal injury can result from escaping fluid under pressure.If a pressure indication is shown on the indicator, push the release valve in order to relieve pressure before removing any hose from the radiator.
Check the coolant level in the cooling system.
Look for leaks in the system. Note: A small amount of coolant leakage across the surface of the water pump seals is normal. This leakage is required in order to provide lubrication for this type of seal. A hole is provided in the water pump housing in order to allow this coolant/seal lubricant to drain from the pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure.
Make sure that air flow through the radiator does not have a restriction. Look for bent core fins between the folded cores of the radiator. Also, look for debris between the folded cores of the radiator.
Inspect the drive belts for the fan.
Check for damage to the fan blades.
Look for air or combustion gas in the cooling system.
Inspect the filler cap, and check the surface that seals the filler cap. This surface must be clean.
Look for large amounts of dirt in the radiator core. Look for large amounts of dirt on the engine. Remove the dirt from the radiator core and the engine.
Fan shrouds that are loose or missing cause poor air flow for cooling.